TB-500
TB-500 (Thymosin Beta-4 fragment; Ac-LKKTETQ, amino acids 17--23 of Thymosin β4)
Access and compounding status raise extra safety and legal questions.
A synthetic peptide related to a natural human protein (Thymosin Beta-4) that promotes tissue repair, reduces inflammation, and supports the growth of new blood vessels. Human clinical evidence exists only for the parent compound; TB-500 itself has no published clinical trials.
This entry is a cited research summary, not an established treatment reference. Dosing language is included as source context, not as medical instruction.
Safety Summary
In the Phase 1 trial of full Thymosin β4 (n=84, PMID 34346165), only mild--moderate AEs were observed across all dose levels (0.05--25 mcg/kg single dose; 0.5--5.0 mcg/kg/day x10 days). No serious adverse events or dose-limiting toxicities. No treatment-related AEs in the Phase 2 ophthalmic trial. Community reports are consistent with mild, transient effects. The most notable theoretical concern is potential tumor promotion via angiogenesis/growth factor activity, though this has not been substantiated in any clinical or preclinical study. Long-term human safety data are not available. The majority of side effect data for TB-500 itself comes from anecdotal community reports.
Clinical check-in
If real-world use or exposure is being considered, review potential interactions, contraindications, and monitoring needs with a licensed clinician rather than relying on summary copy alone.
Sources: [1-5]